title: The effect of emotional content on brain activation and the late positive potential in a word n-back task.
abstract: BACKGROUND
  There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task.
  
  
  METHODS
  We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects.
  
  
  RESULTS
  BEHAVIORAL RESULTS SHOW AN INFLUENCE OF VALENCE ON THE ERROR RATE DEPENDING ON THE DIFFICULTY OF THE TASK: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed.
  
  
  CONCLUSIONS
  Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.
authors.affiliation: Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Kopf
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresler
authors.forename: Philipp
authors.initials: P
authors.lastname: Reicherts
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Herrmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Reif
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology; D001931:Brain Mapping; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D055815:Young Adult